1. Field of the Invention
The present invention relates to a sunlight-detecting sensor for vehicles which measures the amount of sunlight entering a vehicle in order to determine the output of the air-conditioner in the vehicle. Especially, by accurately measuring the angle of incidence at which the sunlight enters the vehicle, it keeps the temperature and the environment inside the vehicle refreshing.
2. Description of the Related Art
In general, almost every vehicle has an air-conditioner mounted inside, which creates a pleasant environment for the driver by adjusting the temperature and humidity inside the vehicle, and various sensors installed in order to control such air-conditioner effectively. Temperature sensors detecting the temperature of the air inside and sunlight sensors detecting the amount of sunlight incident through the car are typical examples of the above sensors.
FIG. 1 is a perspective view illustrating an ordinary vehicle; FIG. 2 is a sectional view illustrating a sunlight sensor developed by conventional technology.
The sunlight sensor by conventional technology consists of the following parts; a housing 110 which occupies a uniform space, a sunlight sensor 120, mounted inside the housing 110, which allows the amount of sunlight incident to be measured, a printing circuit board 120, mounted between the sunlight sensor 120 and the housing 110, which controls the air-conditioner by allowing electrical signals proportional to the amount of sunlight which have been detected and converted into electrical forms by the sunlight sensor 110 to be received by the control part of the air-conditioner via a connector 160, a cover 140, mounted on top of the housing 110, which protects the sunlight sensor 120 and maximizes the amount of sunlight when the angle of incidence of sunlight is at zero degrees by forming a lens part 142 at the center as illustrated in FIG. 3, and a cut-off cap 122, mounted between the cover 140 and sunlight sensor 120, which allows the amount of sunlight on each driver's and passenger's seat to differ accordingly by partly stopping the sunlight entering the vehicle.
Here, the housing 110 can be installed anywhere such as the inside/outside of the vehicle provided that it receives sunlight; however, it is most recommendable to install it at the center of the instrument panel so that the housing is placed inside the front window.
Hereby, the amount of sunlight incident on both driver's and passenger's sides can be measured simultaneously so that the difference between the amount of sunlight incident on each side can be detected easily.
The sunlight sensor 120, as illustrated in FIG. 2, consists of a couple of sunlight sensors arranged by lining up in left/right directions and each sensor 120 is connected to each printing circuit board 130 via wires so that the 1st sensor 120a, installed on the left, detects the amount of sunlight incident on the driver's side and the 2nd sensor 120b, installed on the right, detects the amount of sunlight incident on the passenger's side.
Hereby, while the amount of sunlight incident on the driver's side and the passenger's sides is to be measured independently, the cut-off cap 122 forms a cover shape that covers the sunlight sensor and a glass smaller than a certain size so that when the position of the sun is right above the vehicle i.e. the angle of incidence is zero degrees, as illustrated in FIG. 3, the amount of sunlight incident on both 1st sensor 120a and 2d sensor 120b is identical, and when the position of the sun is down on the left, i.e. the angle of incidence is changed to −90 degrees, the amount of sunlight incident on the 1st sensor decreases and the amount of sunlight incident on the 2nd sensor increases, thereby controlling the operation of the air-conditioner according to this condition by detecting the greater amount of sunlight supplied to the driver's seat compared to that of the passenger's seat.
On the other hand, when the sun is down on the right and the angle of incidence of sunlight changes towards 90 degrees, the opposite to what it was stated above, the amount of sunlight detected on the 1st sensor increases and the amount of sunlight detected on the 2nd sensor decreases, thereby transmitting an electrical signal that allows the air-conditioner to be controlled.
But, in case of a sunlight sensor for vehicles by conventional technology, since the cut-off cap 122 for measuring the angle of incidence of sunlight forms a glass 124 smaller than a certain size and the amount of sunlight on the driver's seat and the passenger's seat is measured by the changes in the angle of incidence of sunlight supplied to the sunlight sensor 120 through the glass 124 above so that the sunlight sensor 120 doesn't detect the sunlight due to the cut-off cap 122 although the sunlight enters inside the vehicle when the position of the sun is either −90 or 90 degrees as illustrated in FIG. 1 and FIG. 3, there is a problem in that it is not possible to carry out an appropriate control of the air-conditioner for the environment inside the vehicle